Today we're quite happy with paper money.
Even more amazingly, we're happy with money we can't even see.
Millions of dollars pass through this woman's hands every day,
or rather, across her computer screen.
She's a foreign exchange dealer, whose business is literally buying and selling money.
Each day around $3 trillion changes hands in transactions like these around the world.
And it's all built on trust.
It has to be when you can't even touch the stuff.